Volatile active compounds such as ethylene response manipulation agents or plant disease and insect controlling materials or other plant growth regulating materials are dispersed in water based mediums and sprayed on crops to improve harvest yield, and subsequent storability of harvested plants and plant parts. These compounds are mostly manufactured in concentrated and generally stable forms by either encapsulation process, or forming salts or conjugated complexes for storage and distribution. The concentrated formulations are then dissolved and diluted to desired application concentrations with water or water based mediums immediately prior to their application on agricultural crops. Once the concentrated compounds are dissolved in water or water based mediums, the volatile active compounds on hydration gets released from the liquid formulation, and are lost to the environment or accumulate in the headspace of the formulation or mixing container, as a result the efficacy of the application solution is reduced. Additionally, under most situations, the complete release of the volatile bioactive compound may take less than 1 hour which makes the biological performance of the liquid application almost ineffective under commercially required spray time of at least 3 to 4 hours. Continued volatile loss from liquid solutions containing bioactive volatile compounds can lead to high vapor pressure buildup in the headspace of mixing tank which can cause explosion and risk workers safety.
U.S. Pat. No. 8,377,489 B2 describes the method of contacting bananas with liquid composition comprising a cyclopropene molecular encapsulation agent complex for a period of 1 to 4 minutes. Since the duration of the liquid contact was small, the authors did not investigate the loss of gaseous 1-MCP from the encapsulated matrix in liquid formulation.
US Patent Application Number 2012/0264606 A1 describes an oil medium for suspending encapsulated MCP particles. The authors then process the suspension in the media mill to produce particles of less than 2 micrometers. When the MCP solution was made from these oil based formulations and then passed through the nozzle of a sprayer, the MCP retention in the spray solution was much better. Authors do not report MCP release kinetics from these oil based formulations. As oils are not miscible with water, producing a homogenous solution to cause consistently a desired effect may be a challenge.
US Patent Application Number 2013/0065764 discloses a formulation which comprises suspended MCP encapsulated materials into non-aqueous organic and synthetic fluids and then bringing the formulation into contact with plant and plant parts. The authors' report that the cyclopropene complex in solution remains in the solid form, minimizing the contact between the cyclopropene compound complex and water, leading to the retention of MCP in the solution for a longer time. The authors do not show any MCP release kinetics data. Moreover, the composition of the disclosed formulations may be inapplicable to ripe or near ripe fruit or plant parts due to the potential for undesirably long residual life of some of the synthetic or organic components of the formulation post application.
The disclosed invention comprises water soluble, environmentally safe and as far as possible, food use approved ingredients that significantly reduce the loss of the volatile active compounds from aqueous solutions leading to sufficient efficacy of liquid formulation or spray solution required to cause a desirable biological effect. The reduction in rapid loss of volatile compounds may help to reduce the volatile accumulation in headspace of mixing tank which can cause potentially explosion hazard in dealing with chemicals of volatile nature. In addition, the invention reduces the resident time of encapsulated volatile 1-MCP compound in the control release 1-MCP liquid formulation from its formation to application onto target plants, thereby, making the spray application more effective, convenient and viable under commercial conditions.